Croatia is investigating whether some of the attackers involved in the November 2015 Paris terror attacks were using mobile phones purchased in Croatia.
Croatian intelligence is cooperating with its French counterparts to determine whether the attackers that killed over 130 people in several coordinated attacks across Paris, were using these phones to communicate with each other. Two of the attackers are believed to have traveled to Europe through the now closed Balkan refugee route, that carried people from Syria, the rest of Asia and Africa, through Turkey and the Balkans. Croatia was one of the key countries along the route which had little security oversight.
Croatian media report that one of the organizers of the attack boasted that he helped carry 80 Islamist fighters from the Middle East to Europe, intermingled among the thousands of refugees and migrants that used the route each day.
The more recent Brussels terror attacks is also still being investigated, but at least one of the suicide bombers that took part in it is also believed to have fought in Syria, and to have used the Balkan route to come back to Belgium. Even Europe born Islamists, who have French or Belgian passports, found the route more convenient to use because it allowed them to raise less suspicion than when traveling with their documents.